1. Field of the Invention
The present invention refers to a hydraulic packing device for wellbores, of the type employed in downhole operations, such as well intervention activities, and which may be combined with other well tools in wells such as production wells, injection well, oil wells, water wells, gas wells and the like, and more particularly it refers to a retrievable hydraulic packer comprising at least one sealing or packing assembly with packer elements and/or at least one anchoring assembly with anchor clamps or slips and/or at least one hold-down slips, which inventive packer may be run into the wellbore and expanded to anchor to and/or seal the wellbore at selective sections of the wellbore as well as it is capable of working with one or multiple sealing and/or anchor assemblies and/or holding assemblies, as well it is capable of being installed and retrieved as desired.
2. Description of the Prior Art
Several well packing devices or packer apparatus are well known in the art, which are currently downhole devices that are generally used to isolate the annulus between the casing or liner and the tubing or conduit for production, injection or treatment and they may include means of securing the packer against the casing wall, or anchor assembly, such as a slip arrangement, and a means of creating a reliable hydraulic seal to isolate the annulus, or sealing or packing assembly, by means of one or more expandable elastomeric elements. The expansion of the elastomeric elements and slips are generally obtained by axially operated compression mechanisms.
When the intervention activity in the well bore has finished and the packer must be released from the sealing and anchoring condition in the casing for retrieval, the compression mechanisms must be released and this operation may be carried out mechanically or hydraulically. In the mechanical releasing of more than one of packers, the stresses along the string impose the use of expansion joints in order not to add individual release efforts in the stress type releasing packers.
Other well packing devices include mechanisms that must be rotated to release the sealing and anchor assemblies. With installations of more than one packer it is almost impossible to rotate de all the string to obtain the individual rotation necessary for each assembly, wherein the sum of all the individual rotations will generate an excessive torque along the entire string.
Another known packer system is the double latch hydraulic packer which comprises a mandrel with a sealing assembly including a plurality of squeezable rubbers and a fastening or anchor assembly with clamps or slips capable of expanding in opposite axial directions to provide up and down anchorage. To release this packer the mandrel and the string connected thereto must be rotated.
To release and retrieve the above mentioned double latch packer several spins or turns must be done to unpack the rubbers and finally disengage the clamps. In wells with even some degrees of inclination or where, as part of the installation, there are also injection devices, it is very difficult, if not impossible, to generate the necessary turns to release the tool without generating high torque in the maneuvering string. It would be even more difficult if the installation includes more than one packer having this release assembly; in that case there would be an addition of the rotation efforts in each of the packers.
Even another type of well known packer is the hydraulic fastening and stress releasing packer. This kind of packer has the feature that, in order to release the tool once it has been fastened, traction must be applied over the mandrel to cut one or more shear pins of a safety assembly and to release the packer completely. If there are installations with several packers, all the packers behave as one string, therefore, the force necessary to cut all the pins is the sum of the forces necessary to cut each pin of the packers, which total force is extremely high. The production strings generally have a limited resistance to these traction forces. In other words, it is necessary to have some kind of intermediate supplementary device to compensate the forces of each packer and not to transmit the force downward to other packer. Another limitation to be taken into account is that, in some of these packers, the mechanical works of the tubing between packers derived from the pressure changes might generate stress or cuts in the safety mechanisms, which would cause an early release of the tools.
U.S. Pat. No. 3,054,450, to Baker, discloses a well packer comprising a packer apparatus A and a setting tool D with a mandrel 54 connected to a first intermediate mandrel portion 56 which is connected to a second intermediate mandrel portion 57. To release and retrieve the packer, Baker provides a tool E that must be inserted once setting tool D is removed. Tool E must be rotated to cause rotation of a sleeve 49 which rotation of sleeve 49 will cause, after several rotations and movements, the rotation of a sleeve 42 on the body threads 44 and feed upwardly along the body 10 (see column 7, lines 24-67). This imposes stresses on the system due to the necessary excessive torque by the rotation of the parts.
In view of the well pacer systems available it would be very convenient to have a new well packer that cab be easily anchored and sealed in a well casing, capable of being combined in a tubing with other pacers and tolls and capable of being released just through a quick disconnection of a quick connection requiring only a short turning of the tubing, preferably a quarter turn, in a manner that such disconnection between an upper mandrel and a lower mandrel can be reinstated into a new connection against rotation between the upper and lower mandrels, thus reinstating the capability of the tubing to follow disconnecting other packers that are installed downwardly in the casing.